STAAR (State of Texas Assessments of Academic Readiness) Algebra I, May 2018, cont.

The State of Texas Assessments of Academic Readiness (STAAR) exam, administered MAY 2018.

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Administered May 2018

Read each question carefully. For a multiple-choice question, determine the best answer to the question from the four answer choices provided. For a griddable question, determine the best answer to the question.





41. The area of a rectangular trampoline is 112 ft². The length of the trampoline is 6 ft greater than the width of the trampoline. This situation can be represented by the equation w² + 6w − 112 = 0.

What is the width of the trampoline in feet?

A 7 ft
B 16 ft
C 8 ft
D 14 ft

Answer: C 8 ft
If the length X the width of a rectangle is 112 ft², what are the possible lengths and widths? Hint: They have to have a difference of 6 because the length is 6 more than the width.

The factors of 112 are (1, 112), (2, 56), (4, 28), (7, 16), (8, 14). The last pair has a difference of 6. The width is 8 and the length is 14.



42. The table shows the linear relationship between the balance of a student’s savings account and the number of weeks he has been saving.

Based on the table, what was the rate of change of the balance of the student’s savings account in dollars and cents per week?

Record your answer and fill in the bubbles on your answer document.

Answer: $7.00 per week
It's a linear relationship, so any two points can give you the rate of change. As always, if I have a chance to use 0 or 1, I'll take it. If I can use smaller numbers instead of bigger numbers, I'll do that, too.

Rate of change: (39 - 32) / (1 - 0) = 7 / 1 = 7
$7.00 per week.

43. The graph of a linear function is shown on the grid.

Which equation is best represented by this graph?

A y + 7 = −3(x − 4)
B y + 1 = −3(x + 2)
C y − 4 = 3(x + 7)
D y − 2 = 3(x − 1)

Answer: A y + 7 = −3(x − 4)
The slope is negative, so choices C and D are eliminated.

According to the other choices, either (4, -7) or (-2, -1) should be a point on the graph. We can see that (4, -7) is on the graph, but (-2, -1) is not. In fact, the graph doesn't even go through any part of Quadrant III.



44. Which expression is a factor of 9r² − 4r + 1?

F 3r − 1
G r − 1
H 9r − 1
J There are no real factors.

Answer: J There are no real factors.
What are two factors of (9)(1) that add up to -4? Answer: there are none.

If you graph this function, you will see that it doesn't cross the x-axis.



45. The graph of 2x − 5y = 10 is shown on the grid.

Which ordered pair is in the solution set of 2x − 5y ≥ 10?
A (0, 5)
B (5, 0)
C (−2, 5)
D (−5, 2)

Answer: B (5, 0)
Look at the point (0, 0). Is 2(0) - 5(0) ≥ 10? Is 0 - 0 ≥ 10? Obviously not. So (0, 0) is not is the solution set. Therefore, the solution is not above the line, but below the line. So which of these points is pn or below the line?

The other way to look at it is this: Plot the four points. Choice A is above the line. Choice B is on the line. Choice C is above the line. Choice D is above the line. Three of the choices are above the line, which means that they are ALL solutions or NONE of them are solutions. Since they can't all be, then none of them are. The answer is B.

More to come. Comments and questions welcome.

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